Roof Drain Layout

From the edge of a valley.

Roof drain layout.

The roof is sloped towards the drain through either tapered insulation or through joist modifications below the roofline. Install a drain at most 50 ft. From a roof edge. Following are some basic design guidelines to consider as part of your project courtesy of jay r.

The next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout. Use at least two drains where possible. Roof drains zurn plumbing products groupspecification drainage operation 1801 pittsburgh avenue erie pa 16502 phone 814 455 0921 fax. This form of roof drainage is preferred if a clean exterior appearance is desired.

Limit roof area to 25 000 sq. General roof drain system guidelines. Most draining systems on flat roofs have a poor design or are not correctly installed. Install a drain at most 50 ft.

It is very critical to position drains for maximum effect. These will drain to somewhere near the center of the roof and down through the building to underground storm mains or a detention pond. The sizing of roof drains must be large enough to quickly carry away all water entering the roof drains. The full flow capacity of a drain is not realized until the water reaches approximately 2 5 above the inlet in a four inch drain and 3 5 in a six inch drain.

Factors which affect proper roof drainage are deck slope drain size and placement of drains.